Deoxidizing apparatus



2 Sheets-Sheet 1 DEOXIDIZING APPARATUS Filed Sept. 28, 1923 C. J. RODMANET AL Sept. 28 1926.

I I!!! V ATTORNEY s R O T N E v m C/arenc e J Raom an.

L e/ana H. Hi/l.

WITNESSES:

C. J. RODMAN ET AL DEOXIDIZING APPARATUS Sept. 28 1926.

Filed Sept. 28, 1923 2 Sheets-Sheet 2 lNVENTOR Clarence J. Rod/nan. Le/and H. Hill. BY

ATTORNEY ing oil.

Patented Sept. 28, 1926.

UNITED STATES PATENT OFFICE.

ULARENCE j. RODMAN AND LELAND H. HILL, 0] WILKINSBURG, PENNSYLVANIA, AS-SIGNORS T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORA-TION OF PENNSYLVANIA.

DEOXIDIZING APPARATUS.

Application filed September 28, 1923. Serial No. 665,408.

Our invention relates to deoxidizing apparatus and it has particularrelation to respirators for deoxidizing the air within the casings ofelectrical apparatus, such, for example, as transformers, circuitbreakers, or the like.

Our invention has, for one of its objects, to provide a simple andreliable apparatus for effectually removing oxygen from the an initiallyin or entering the casings of electrical apparatus.

A second object of our invention Is to provide a deoxidizing apparatusof the character described above, in which the length of the path oftravel of air or gases therethrough and the drop in pressure causedthereby are reduced to a minimum.

In the operation of transformers, circuitbreakers and similar electricalapparatus employing oil or other hydrocarbon compounds for insulatingpurposes, it has been found that the vapors and the gases arising fromthe volatilization or the breaking down of the oils constitutes anexplosive mixture that is a source of danger to property and tooperating personnel. Such gases may collect in the space above the oiland may be exploded upon the occurrence of an arc arising by reason of ashort circuit or other condition.

It has been demonstrated that the danger of explosions of the characterset forth above may be substantially entirely eliminated ifsubstantially no oxygen is present in the air or gas occupying the spaceabove the insulat- In accordance with the present invention, thiscondition is obtained by employing a respirator or deoxidizin apparatusthat is provided with a suita le material for removing oxygen from theair originally within the tank or from such an as may enter the tank byreason of changes in volume of the oil caused by variations intemperature.

In the accompanying drawings,

Figure 1 is a view, partially in section and partially in elevation, ofa transformer with our invention applied thereto;

Fig. 2 is a view in transverse section, taken along the line 22 of Fig.1;

Fig. 3 is a view, similar to Fig. 1, of a modified form of ourinvention; and

Figs. 4, 5 and 6 are views in transverse section of modified forms ofthe deoxidizing apparatus.

' Referring to Figs. 1 and 2, a transformer 1 is rovided with a casing 2having a cover mem er 3 through which the terminals of the transformerextend to suitable condenser bushings 4 and 5. The casing 2 is filledwith oil, in icated at 6, to any desired level above the transformerproper.

A respirator or deoxidizing apparatus 8 that is attached to the sidewall of the casing 2 and that is in communication with the air space 9above the oil comprises an outer casing member 10 having a removablecover 11 and a removable bottom member 12 and a container 13 fordeoxidizing and dehydrating material that is provided with side walls ofperforated material, which may be, for example, sheet metal, expandedmetal, woven material, or other similar or suitable materials. Thecontainer 13 is provided with a suitable deoxi'dizing material indicatedat 14 that is preferably that constituting the subject-matter of thecopending application of C. J. Rodman and A. H. Maude, Serial No.652,668, filed July 20, 1923, and assigned to the Westinghouse Electric& Manufacturing Company. The container 13 is so disposed within thecasing 10 that its front and ack walls are spaced therefrom, except thatthe upper edges of the walls are secured to the casing. The edges of thewall portions of the container are connected to the side walls of thecasing 10. The container 13 is so completely filled with deoxidizingmaterial 14 that it constitutes a partition for dividing the spacewithin the container 10 into two compartments 16 and 17, communicationbetween which may be had only through the deoxidizing material 14. Thecompartment 16 communicates with the interior of the transformer casingby means of a screened opening 18 in the latter. The com artment 17 isconnected to the atmosphere t rough a relief valve 19 for regulating thebreathing of the transformer through the respirator.

The relief valve 19 is substantially that constituting thesubject-matter of the copending application of L. H. Hill, Serial No.608,791, filed Dec. 23, 1922, and assigned to the Westinghouse Electric& Manufacturing Company. The valve 19 is similar in prin ciple to thatof the well-known U-tube, except that the pressures at which it mayoperate in the respective directions differ in accordance with the headsof liquid to be overcome.

The relief valve 19 comprises a container or receptacle 21 for asuitable liquid, such, for example, as mercury, to constitute a liquidseal. The valve is also provided with an air inlet tube 22 and an .airoutlet tube 23, the former of which is connected to the space above theliquid and the latter of which extends below the surface of the liquid.A spillway tube 24 returns any liquid carried up the tube 23.

This arrangement provides that the pressure necessary to permit air toenter the outlet tube and pass through the receptacle 21 and tube 22 isthat equal to the head of liquid in tube 23. The pressure necessary forair or gas to flow in the opposite direction is dependent upon therelative horizontal crosssectional areas of the tubes 23 and 24 and thereceptacle 21, since the level of the liquid in 'the receptacle must bedepressed by being forced up the tubes 23 and 24 until the open end ofpipe 23 is uncovered. By way of example, the degree of vacuum requiredto draw air through the respirator 8 and valve 19 may be one-fourth ofone pound, while a pressure of five pounds above atmospheric pressuremay be necessary to expel gas or air from the transformer.

It may be desirable to obtain a sample of the gas within the transformerin order to determine its content of oxygen. Accordingly, I provide apipe 26 extending from the opening 18 through the compartment 16 andinto the casing 27 of the relief valve; the end of the pipe beingprovided with a suitable. stop-cock 28.

It may be assumed that the transformer is being placed in operation. Theheat losses in the transformer windings and the core member increase thetemperature of the surrounding oil and the latter expands tocorrespondingly increase the pressure of the air or gases within thespace 9. When the pressure exceeds the predetermined value for which thevalve 19 is arranged, air is expelled through the respirator and valve19 into the atmosphere.

In case the temperature of the transformer falls, such, for example, asby reason of varying load conditions, the volume of the oil decreasesand the pressure of the air within the s ace 9 falls below atmosphericpressure. en the difference in pressure reaches a predetermined value,the valve l9 admits air into the compartment 17 and through thedeoxidizing material 14, the

compartment 16 and o ning 18 into the space 9. Theair entering thetransformer is effectually deoxidized and dehydrated,

. substantially pure dry nitrogen being supplied thereto. The result isto fill the space above the oil with a as that is inert and to therebyremove all diinger from explosions by reason of the formation ofexploslve mixtures that might otherwise exist.

In the modification shown in Figs. 3 and 4, a container 30, fordeoxidizing material, differs from the container 13 of the apparatusshown in Fig. 1 in that it is cylindrical in form and is provided with ahollow bore, indicated at 31, that communicates with an opening 32 inthe transformer casing. The container 30 is illustrated in the form of asheet-metal member having perforations 21 therethrough. The valve 19 ofFig. 1 is diagrammaticall represented by a U-tube 33 of conventionadesign. The operation of this form of my invention differs in nomaterial respect from that of the form shown in Fig. 1.

In the apparatus shown in Fig. 5, the container 35 is rectangular incross-section similarly to the container 13 of Fig. 1, but it isprovided with a central bore 36, which corresponds to the circular bore31 shown n Fig. 4.

n the arrangement shown in Fig. 6, two cylindrical containers 38 areemployed, each of which corresponds to the container 30 of Figs. 3 and4. A single controlling valve, such as the valve 19 in Fig. 1, maycontrol the admission of air to the exterior surfaces of the containers26. This arrangement differs from that of Fig. 4 principally in that agreater surface of deoxidizing material is presented to the incomingair, and the capacit of the respirator is increased correspon ngly.

Respirators constructed in accordance with my invention com rise few andsimple parts which may be rea ily assembled and in which the deoxidizingmaterial may easily be replaced when desirable or necessary- The removalof the bottom plate 12 permits the used material to be discharged. Therespirator is so arranged that the air or gases passing therethroughtraverse a path of minimum length but of large cross-sectional areawhereby the resistance to exchanges of air between the transformer andthe atmosphere is very sli ht.

The deoxidizing material is very closely adjacent to the space above theoil and the air initially within the transformer tank is readilydeoxidized by diffusion. The respirator occupies very little spaceradially of the transformer and this feature renders our improved devicepeculiarly adaptable for use in connection with transformers of theradiator type wherein space is limited.

We claim as our invention 1. In a deoxidizing apparatus, the combinationwith a casing having a plurality of openings, of a perforated containerfor deoxidizing material so disposed in' said casing that any fluidexchanged between said openings must traverse said container.

2. The combination with a tank having fluid enclosed therein, of, adeoxidizing apparatus com rising a container for deoxidizing mate riahaving one surface communicating with the tank and another surfacecommunicating with the atmosphere, and a valve for automaticallycontrolling the communication with the atmosphere.

3. The combination with a tank of a casing communicating therewith anthe atmosphere, a perforated container for deoxidizing material in saidcasing having side walls spaced from said casing and respectivelycommunicating with said tank and said atmosphere.

4. The combination with a tank having a fluid enclosed therein, arespirator connected to said tank, said respirator com risin a. casing,a perforated container for eoxi izing material having surfacescommunicating ony with said fluid and with the atmosphere, and means forpermitting a transfer of fluid between the tank and the atmosphere underredetermined pressure conditions.

5. The combination with a casing, of a. container for deoxidizingmaterial therein, said container having certain portions spaced fromsaid casing and certain other portions sealed to.said casing whereby thecontainer divides the space within said casin 6. The combination with acasin of a container for deoxidizing material sposed longitudinallytherein to divide its space, said casing having openings forrespectively communicating with the sides of said container wherebyfluid traversing said openings passes through said container.

7. The combination with a casing of relatively small transversecross-sectional area,

' with' of a container for deoxidizing material dis- 8. In combinationwith a tank partially filled with oil and having a gas-filled spacetherein, a breathing apparatus comprising a casing provided with aporous container and means 1n said container for deoxidizing said gaswhen said gas passes into said space.

9. In combination with an oil-filled tank, having a gas-filled spacetherein, a breathing apparatus com rising a casing, means for permittingexha ation from and inhalation into said space, a porous partition in.said casing in contact with the gas in said space on one side thereof,and communieating with atmospheric air on the other side thereof, andmeans contained between the outer walls of said partition fordeoxidizing inhaled gas.

10. In combination with an oil-filled tank having a gas-filled spacetherein, a breathing apparatus comprising a casing, means for permittingexhalation from and inhalation into said space, a porous partition insaid casing in contact with the gas in said space on one side thereofand communicating with atmospheric air on the other side thereof, and amixture of oxygen reducin chemicals between the outer walls of saidpartition.

In testimony whereof we have hereunto subscribed our names this 22nd dayof September, 1923.

CLARENCE J. RODMAN. LELAND H. HILL.

